Central processing unit



FIG. 1 is a front elevation view of a central processing unit showing mynew design;

FIG. 2 is a right side elevation view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a rear elevation view thereof;

FIG. 6 is a bottom plan view thereof; and

FIG. 7 is a top, front, right side perspective view thereof.

The ornamental design for a central processing unit, as shown anddescribed.